1,400 millirem per exam
1,300 millirem per year 1,100 millirem per exam 650 millirem per exam 620 millirem per year 509 millirem per exam 405 millirem per exam 245 millirem per exam 200 millirem per year 170 millirem per year 150 millirem per exam 110 millirem per exam 100 millirem per year 40 millirem per year 31 millirem per year 30 millirem per exam 15 to 20 millirem per year 11 millirem per year 9 millirem per year 7.5 millirem per year 6-8 millirem per exam 5 millirem per year 4 millirem per year 3 millirem per exam 2 millirem per year 1 to 6 millirem per year 1 millirem per year 1 millirem per trip 2 millirem per trip 1 millirem per year 0.5 millirem per bag 0.3 millirem per year 0.2 millirem per year 0.1 millirem per year

Most radiation comes to us from the sun and from cosmic radiation – so that people at higher elevations like Colorado and adjacent Rocky Mountain States receive more than those who live at sea level. However, a lot of radiation also comes from the soil and rocks around us. Granite and marble have background levels of radioactivity. A relatively small additional amount comes from our man-made technology.

Is a radiation dose of 620 millirem (or 0.62 Rem) in a year harmful?

No. No effects have ever been observed at doses below 5,000 millirem (5 Rem) delivered over a one-year period. In fact, effects seen when humans are exposed to 100,000 millirem (100 Rem) over a short time period are temporary and reversible. It takes a short-term dose of well over 500,000 millirem (500 Rem) to cause a fatality.

For more information on radiation and DHEC’s role in response, contact: